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Mexican Wolves, Wild Once Again
by Cheryl A. Sweet

Amid two feet of snow and a media mob in eastern Arizona, a family of three edged closer to freedom. While the adult female and her year-old daughter tentatively stepped outside their steel crate and into an outdoor pen, the four-year-old adult alpha male remained reluctant to emerge. Only after the reporters, photographers, television crews, and other observers departed an hour later did the large Mexican gray wolf (Canis lupus baileyi) venture outside his crate, warily sniffing the air. He spotted his waiting mate and pup, and the family reunited with whimpers, licks, and wagging tails.

Mexican wolf at the National Zoo
A Mexican wolf at the National Zoo. (J'nie Woosley/NZP)

The highly anticipated January 1998 release of these three wolves and eight others into pens near Alpine, Arizona, officially launched the reintroduction of endangered Mexican gray wolves into the U.S. Southwest. It was the penultimate step toward liberation for the wolves, which were born in a breeding facility in New Mexico. They remained in their remote enclosures for two months, feeding on road-killed prey while they adjusted to their new environment.

On March 29, 1998, they became the first free-roaming Mexican wolves in half a century when they were released in southeastern Arizona. With haunting howls, they reclaimed part of their long-lost range: nearly 7,000 square miles of public land in southeastern Arizona's Apache National Forest and southwestern New Mexico's adjoining Gila National Forest. Known as the Blue Range Wolf Recovery Area, this prey-rich, drought-resilient region of ponderosa pines is surrounded by steep canyons, high ridges, and boulder-strewn hillsides that breeding wolves can use as denning sites.

Despite the landmark accomplishment of returning the Mexican wolf to its historic habitat, celebrations were short-lived. Controversy had troubled the two-decade-long reintroduction planning process, but choreographing the wolves' comeback in the wild was about to grow even more contentious.

The Lost Lobo
Mexican gray wolves are the rarest, smallest, and most genetically distinct of North America's gray wolf subspecies, and the most endangered gray wolf subspecies in the world. Typically weighing between 60 and 80 pounds, the Mexican gray wolf—or lobo—is about the size of a German shepherd, and sports a blended black, white, and gray coat. While thousands are thought to once have roamed throughout Mexico, Arizona, New Mexico, and Texas, Mexican wolves today occupy less than one percent of their former Southwest range, living mostly in zoos.

The Mexican wolf's dramatic decline began in the 1500s, when European settlers introduced cattle and other livestock to its historic range. One theory on the cause of their decline postulates that when ranchers began killing wolves that preyed on their livestock, they broke up wolf packs, leaving loners that could not hunt as efficiently on their own. These loners may have gravitated toward easy prey like cattle; the more livestock they took, the angrier humans became, and wolves were killed with increasing frequency. Another theory suggests early settlers depleted stocks of large game such as bison, deer, elk, and moose, so gray wolves turned to livestock for sustenance, and were consequently persecuted by humans.

Whatever the cause, anti-wolf sentiment grew so strong that in the early 1900s, the federal government began funding an intense wolf eradication crusade throughout the United States that included trapping, shooting, and poisoning the wolves with strychnine, arsenic, and sodium cyanide. By the 1940s, there were fewer than 100 Mexican wolves in the country, and the last known Mexican wolf in the United States was shot by a Texas hunter in 1970.

Mexican wolves were extinct in the wild in the U.S. by 1970. (Jessie Cohen/NZP)

In general, wolves' luck lapsed long before the U.S. government's elimination efforts. Maligned by fables and folklore for centuries, wolves suffered serious image problems. Medieval tales of wolves feeding on children generated fear and loathing of anything lupine, and during that time, people suspected of being werewolves were executed in France, Spain, and Russia. Even today, fairy tales about Little Red Riding Hood and stories such as the huffing and puffing canine who collapsed the three little pigs' pad continue to shape European and American attitudes about wolves. "Unfortunately, I think American public opinion is still colored by the Big Bad Wolf," says Terry Johnson, an endangered species coordinator for the Arizona Game & Fish Department.

When Johnson began exploring reintroduction possibilities in the early 1980s, "It wasn't socially acceptable to talk about wolf reintroduction," he recalls. "Anti-wolf feelings were abundant among game managers and the ranching community, while state and federal agencies wouldn't touch this issue with a ten-foot pole."

An Uncertain Beginning
The U.S. Fish & Wildlife Service (USFWS) listed Mexican wolves as endangered in 1976, three years after passage of the Endangered Species Act. In 1982, U.S. and Mexican federal wildlife agencies signed the Mexican Wolf Recovery Plan, calling for the return of 100 wolves to the wild by 2008.

The 11 wolves released in 1998 got off to a rocky start—four were shot illegally and a fifth was shot in what was deemed legal self-defense—within the first year of release. By 2001, a three-year review found the reintroduction project wasn't progressing as anticipated. It was mired in management problems, lawsuits, and mounting public criticism. Says Johnson, "We weren't doing enough outreach and therefore didn't have the public participation we needed at that point."

A more collaborative management effort was forged in 2002 between the project's key players: the Arizona Game & Fish Department, the New Mexico Department of Game & Fish, the USFWS, the U.S. Department of Agriculture (USDA) Forest Service, the USDA Wildlife Service, and the White Mountain Apache Tribe. Among management's chief priorities was addressing a lengthening list of complaints to increase acceptance—and ultimately success—of wolf reintroduction.

Complexities and Controversies
Mexican wolves are designated as "nonessential, experimental populations" under a provision of the Endangered Species Act, meaning that Mexican wolves preying on livestock can be legally killed by ranchers under precisely prescribed conditions, or killed, captured, or translocated by the USFWS. Additionally, wolves with three livestock killings, or depredations, within a year are permanently removed from the wild. Of the 44 Mexican wolves involved in known depredation incidents through 2003, 20 percent are currently in captivity.

Livestock carcasses present another difficulty. While wolves found feeding on carcasses aren't always responsible for the killings, a recent report by the Mexican Wolf Reintroduction Project's Interagency Field Team shows 90 percent of these wolves are eventually involved in livestock depredations. The report advises ranchers to remove livestock remains before wolves scavenge them and become habituated to killing cattle.

The business of boundaries is also touchy. Wolves wandering outside the designated recovery area must be translocated, captured, or killed according to the wolves' experimental-population status in the Endangered Species Act. Critics of this policy contend that widely dispersing wolves sometimes travel up to 200 miles a day—especially when seeking mates—so wolves should be allowed to roam outside designated boundaries. Capturing wolves, they argue, slows recovery by hindering the colonization of new areas.

The reintroduction project's five-year review, targeted for completion by the end of this year, is expected to address these and other concerns.

Captive Breeding
Between 1976 and 1980, the USFWS sent a trapper to Mexico to capture the last known five Mexican gray wolves in the wild, and bring them to the Arizona-Sonora Desert Museum to start a captive breeding program. Two other genetic lines were found in Mexican wolves in captivity and were added to the breeding population in 1995. By 1998, the initial founding population of seven wolves had grown to 182. Today, the Mexican Wolf Captive Breeding Program, managed by the American Zoo and Aquarium Association's (AZA) Species Survival Plan (SSP) for Mexican wolves, houses 309 wolves in 48 zoos and sanctuaries in the United States and Mexico, and there are probably about 50 or 60 wolves in the wild.

As one of the Mexican wolf SSP-participating facilities, the Smithsonian's National Zoo acquired three male Mexican wolf siblings—Tika, Lakota, and Cheveya—in 2001 from the Wild Canid Research and Survival Center in St. Louis. When Lakota challenged the dominant male, Tika, serious fighting ensued, so Zoo staff moved Lakota to a separate enclosure adjacent to his brothers'. The Zoo's Mexican wolf exhibit is not designed to house two separate groups of wolves, so Lakota will be transferred to Mexico's Guadalajara Zoo within the year, where he and a female will become one of only six Mexican wolf pairs that managers plan to breed this year.

A biologist examines wolf tracks. (George Andrejko/Az. Dept. Game & Fish)

Seven-year-old Lakota's genes are underrepresented in the Mexican wolf population, and the AZA hopes he and the Guadalajara female will mate, so that his valuable DNA will be incorporated into Mexican wolf populations through his pups and their offspring. "Lakota's descendants may live out in the wild someday," says biologist Linda Moore, the National Zoo's Mexican wolf SSP representative.

Preserving Mexican wolves' genetic diversity is a key captive breeding goal. "Within wolves' genes are the tools for adapting to nature," notes Peter Siminski, coordinator of the AZA's Mexican wolf SSP and wildlife biologist at the Living Desert in Palm Springs. "A captive wolf with rare genes becomes the goose that lays the golden egg. When you're conducting reintroduction, you don't want to put out your most genetically valuable animals, because they could be lost. Instead, you release wolves with the most common genes in the captive population."

Potential release candidates are selected from zoos and sanctuaries that participate in the Mexican wolf SSP, and sent to three U.S. prerelease breeding facilities, where they are evaluated for their genetic makeup, reproductive performance, and behavior. Also known as halfway houses, these facilities are Wolf Haven International in Tenino, Washington; Ladder Ranch Facility in New Mexico; and the USFWS facility at the Sevilleta National Wildlife Refuge, also in New Mexico.

Seven one-third- to one-half-acre wolf pens at Sevilleta sit in an isolated canyon, about an hour's drive south of Albuquerque. It takes another 45 minutes to reach the wolves. Public access and caretaker contact is prohibited so the wolves won't become habituated to humans. "Today's captive-raised wolves are better suited for the wild than the first wave of wolves seven years ago that received too much keeper contact," says Johnson. But, he admits, "while we've worked hard to minimize human contact, a wolf raised in captivity is still infinitely less adaptable than a wolf born and reared in the wild."

Colleen Buchanan was Sevilleta's chief caretaker for six years and later became the USFWS' assistant Mexican wolf coordinator. At Sevilleta, she spent hours atop a cliff, unobtrusively observing Mexican wolves in pens 300 yards below her. With binoculars and a spotting scope, she scrutinized the wolves' behavior to evaluate which were best suited for the wild. Skittish and shy animals are better release candidates than wolves curious about humans. "We harass the heck out of wolves showing any interest in humans by forcefully running toward them, screaming, throwing a rock, or doing whatever we can to let wolves know coming up to us is unacceptable behavior." Besides shyness, pair-bonding and pup-rearing behaviors are viewed as markers for sustained survival in the wild.

Modifying Releases
Buchanan experienced mixed emotions when she was involved with the release of the first wolves into the wild in 1998. "I was elated that they were going to have their shot at the wild. In the back of my mind, though, I was filled with worry and uncertainty because we knew we were putting wolves in an area where people weren't accepting of them."

After five wolves were shot the first year, techniques were tweaked to get wolves farther away from potential contact with humans. Instead of the heavy chain-link prerelease pens used in the beginning of the reintroduction program, Mexican wolves are now released in plastic mesh pens. Mules can carry these lighter pens and the wolves on unpaved wilderness paths instead of roads, and the pens are easily erected in remote regions. Wolves can release themselves from the pens by tearing through the mesh.

Carrying a wolf to an acclimation pen for the first Mexican wolf release in 1998. (Frosty Taylor/Az. Dept. Game & Fish)

While wolves initially spent up to two months in acclimation pens at release sites in the early days of the reintroduction program, today's stays are significantly shorter. Now, wolves decide when they want to leave the pens, and some venture outside just seconds after they arrive, although the program's biologists prefer that the wolves settle down and realize their families are nearby instead of taking off by themselves. "The problem with the initial release of Mexican wolves," adds Buchanan, "is that they're naïve from being in captivity all their lives, and it takes them time to get their footing and figure out how to stay out of trouble."

Finally Free
Besides ensuring wolves' protection while adjusting to the wild, visual observations, ground and aerial radio telemetry, and howling surveys give biologists information about new pack formations, uncollared wolves, den and rendezvous sites, pup presence, and signs of carcasses.

Until newly released wolves hone their hunting skills, they're fed carcasses of elk and deer killed by vehicles on nearby roads, along with commercial carnivore logs. Supplemental feeding is typically discontinued a few weeks after release, to encourage the wolves to hunt and to discourage them from associating humans with food.

The biggest challenge for captive-raised wolves is finding food, notes Buchanan, and their instincts may take time to emerge. Learning to hunt large animals—including 600- to 800-pound elk, their primary prey—is dangerous. "We see broken ribs and legs because they get trampled on. It's not an easy living for them," she says. She also notes that, in general, wolves make many more unsuccessful attempts to kill prey than successful ones.

Mexican wolves can run up to 35 miles per hour, and they hunt in groups. They grasp prey with long, sharp, slightly curved teeth and scissor off pieces of meat that can be swallowed in manageable chunks. With powerful jaws, they crush bones to get to the soft marrow, leaving little waste. Besides elk, Mexican wolves dine on white-tailed (Odocoileus virginianus) and mule (O. hemionus) deer, pronghorn antelope (Antilocapra americana), Rocky Mountain bighorn sheep (Ovis canadensis), javelinas (Pecari tajacu), jackrabbits (Lepus spp.), rodents, and fruits and berries. The wolves also engage in feast-or-famine binges, gorging on as much as 22 pounds of food at a time, then fasting for days.

With a limited number of Mexican wolves in the wild, it's too early to assess the ecological effect of their reintroduction, but scientists speculate it could eventually mirror that of gray wolves reintroduced to Yellowstone in 1995 and 1996. Elk carcasses left by wolves are scavenged by ravens, eagles, and bears; in Yellowstone, gray wolves have culled elk populations near streams, and with fewer deer browsing the vegetation there, even the landscape is changing.

Will Mexican Wolves Rebound?
Many wolf proponents were disappointed when #511, the female wolf that was the most successful breeder in the wild, died. Recognized as the symbol for Mexican wolf recovery, #511, also known as Brunhilda, was the last of the original 11 wolves released in 1998 that remained in the wild. She was the reintroduction project's poster wolf, and her widely disseminated photo was snapped in March 1998 as she stepped out of her pen toward freedom. Her family's fate also saddens many. A litter of pups she whelped in May 2003 did not survive past three or four weeks of age, and her first mate was killed by a hit-and-run driver in September 2003. In June 2005, Brunhilda and her second, wild-born mate and their pups were removed from the wild and transferred to Sevilleta because they were preying on livestock; in the process, her mate was injured. She died at Sevilleta in July 2005.

Brunhilda marked many milestones in the reintroduction program: She was the first born at Sevilleta, and one of the first released in 1998. To Buchanan, she also epitomized the debate over keeping the wolves within boundaries; she was the first wolf to leave the Blue Range Wolf Recovery Area and had to be recaptured and returned to the designated area. "She was the one who demonstrated the folly of this artificial boundary that wolves can't step outside," says Buchanan.

Brunhilda's death was not the project's only disappointment: In 2003, 13 wolves were killed by gunshots, vehicle collisions, and other causes, resulting in a 20 percent population decline from the previous year. Although the project aimed to have 68 wolves in the wild by December 2004, only 22 wolves in nine packs, five lone wolves, and an unknown number of uncollared wolves remained in the wild by the end of July of that year. "We may be looking at the second extermination of the Mexican gray wolf. It's that bad," says Michael Robinson, coordinator of carnivore conservation at the Center for Biological Diversity.

Buchanan says the recovery program is facing some of the most challenging times it has ever seen, as ranchers, landowners, and conservationists grow increasingly discontented with it. "We can't do enough to recover wolves from the environmentalist perspective, but we're doing way too much from the viewpoint of ranchers, who don't want any wolves in their area," she says. "Finding that middle ground, while still meeting the mandate of the Endangered Species Act to recover wolves, is tricky."

Despite these setbacks, says Buchanan, "we keep seeing glimmers of hope." Encouraging signs include the formation of a new pack in May 2005, led by two wolves in Arizona that the USFWS is aware of but has not radiocollared. "This was a wild and naturally forming pack, which is the ultimate objective of the recovery effort," she says.

A recent breeding breakthrough is another bright note: In May 2005, for the first time ever, living pups were born to an artificially inseminated female Mexican wolf at the St. Louis-area Wild Canid Survival and Research Center. The technique could one day help rebuild Mexican gray wolf populations.

Reintroduced wolves must learn to hunt and find water to survive in the wild. (Jessie Cohen/NZP)

Meanwhile, it seems some people's aversion to wolves hasn't changed much in the last two decades. Public meetings were held in Arizona and Mexico in July to discuss proposals to kill wolves involved in three livestock depredations, and one-year moratoriums on releasing new wolves and relocating wolves that kill livestock. Many of the concerns voiced at these meetings were familiar. "You could have taken meetings from 1987 and replayed them, and they would have been the meetings in 2005," says Johnson. Fear for human safety is among the recurring themes, but Johnson says the likelihood of a Mexican wolf attacking a human "ranks somewhere on the order of 1,000 to one million times less significant than attacks by Africanized bees or lightning strikes. You're more likely to die while driving to the grocery store than of being killed by a wolf in the wild."

Buchanan says that wolf foes and fans need to find a middle ground between their extreme beliefs. While some landowners and ranchers perceive wolves as vicious, ferocious beasts, some environmentalists view them as mythical creatures capable of nurturing human children rather than eating them. "Wolves are neither of those. They're just predators trying to make a living, like any other creature out there. They have their niche, which is to serve as the top predator in the ecosystem," she says.

The number of Mexican wolves needed in the wild for a full recovery of the subspecies has not been officially determined. L. David Mech, the world's top wolf biologist and a senior scientist with the U.S. Department of Interior, estimates that 300 Mexican wolves in three separate populations surviving in the wild for three consecutive years would constitute recovery success. That goal will likely be achieved within 30 years, speculates Mech, who has been studying wolves for almost 50 years and has written nearly a dozen books about them.

What continues to captivate Mech about wolves after all these years? "I'm much taken by the challenge they face earning a living, even in areas where humans are an issue. Once they get going, they still manage to survive." Admiration for the wolves also drives Johnson, who has committed two decades to Mexican wolf recovery. In August, while camping with his family near the recovery area in Arizona, he heard his first wolf howl in the wild. "At 2:30 a.m., I was awakened by a gorgeous wolf howl that went on a long, long time. It seemed like an eternity and was totally satisfying. It means wolves are back in nature. I knew this is what I've been working for and what the project is all about."

As one of the reintroduction project's chief architects, Johnson never wavers in his commitment to Mexican wolves' survival, even when the idea of their recovery initially appeared outlandish to almost everyone. He remains resolute about their fate: "I think both ranching and wolf conservation can be accommodated in the Southwest. The only significant obstacle to wolf recovery is the limits of human tolerance. Whether we're ultimately willing to share space with wolves remains to be seen."

—Cheryl A. Sweet is a freelance writer living in Phoenix, Arizona.

ZooGoer 34(1) 2006. Copyright 2006 Friends of the National Zoo. All rights reserved.

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